One specialist type of electrosurgical instrument has one or more electrosurgical electrodes at the distal end of a flexible shaft. Such an instrument is particularly suited to the treatment of joints, particularly the hip joint, as the articulation of the shaft allows the electrodes to reach otherwise inaccessible areas of the joint. U.S. Pat. No. 6,283,960 is one example of this type of instrument.
The shaft typically contains at least one section with greater flexibility than other sections of the shaft. This section of the shaft is normally manufactured to have lower bending stiffness, or with a “weak section”, with less material being present so as to provide greater flexibility. Typically material is removed to form slots, grooves or other cut-outs, to enable the shaft to flex more easily at this section of the shaft.